An Islamic State "kill list" with the names, addresses and photos of American military members has triggered a federal investigation, the White House confirmed -- and one military spouse told Fox News she's already heard from someone, who said they were with NCIS, urging her family to be vigilant.

The military spouse, who was willing to discuss details on the condition of anonymity because she says her family fears for their safety, said the information posted by ISIS sympathizers is accurate -- and she knows several other families identified on the web by the terror group. The original posting listed information for dozens of American servicemembers and called on ISIS sympathizers to kill them. 

"We had a call from an NCIS agent on Saturday who said we were on the 'ISIS kill list,'" the military spouse told Fox News. "The agent wanted to verify our name and address as accurate. He said the threat should be considered. We need to be vigilant, but there was no guidance on what to do and no meeting in person to do a security assessment of our home." 

Based on conversations with other families, the spouse said at least a handful of names are directly connected to the U.S.-led air campaign over Iraq and Syria targeting ISIS. Their husbands are pilots or are connected to the aircraft carriers. They believe the photos were pulled from open source material and media reporting about the campaign and the military. 

White House Press Secretary Josh Earnest said at Monday's briefing that it doesn't appear any information system was breached. He said it appears the information was taken from social media. 

He confirmed the FBI is the lead investigator here, and said the Obama administration is in touch with branches of the military to ensure steps are taken to notify personnel.

"We obviously take the safety and security of our military personnel very seriously," Earnest said. 

The military spouse who spoke with Fox News, however, disagreed with the White House claim that the images were from social media, telling Fox News that "the way it is being presented implicates the service members when, in fact, many of these photos were published by the Navy PR machine." 

She also said there was no immediate contact from the FBI, and the family has not heard what the bureau and NCIS may be doing to verify and thwart any threat directed toward military families. She said an in-person meeting is now expected from the FBI and NCIS, but it comes several days after the "ISIS kill list" was posted. 

"I don't know whether to let our kids play basketball out front of the house," she said of her family-friendly Virginia neighborhood. "I don't know if we can get housing on base. But moving onto base would be letting ISIS intimidate us and win." 

A defense official told Fox News that "each service is doing notifications for service members whose IDs were posted by ISIS/ISIS affiliated hackers," adding that Twitter and YouTube agreed to take down the posting. The U.S. Cyber Command is also investigating. 

"The safety our service members is always a concern. We always encourage our personnel to exercise appropriate [operational security] and force protection procedures," the defense official explained. 

A Navy official said every effort is being made to meet with the families in person but confirmed they did have to make some phone calls when in-person meetings were not possible. 

"NCIS is actively evaluating this threat reporting and working with law enforcement and U.S. intelligence partners to address this incident," the official said. "NCIS has met with almost all named Navy and Marine Corps service members to notify them of this threat and discuss their concerns."

The Navy has already posted a set of social media guidelines on its website urging servicemembers not to share such information as their address and deployment status. 

Concerns that ISIS sympathizers could use social media to target U.S. servicemembers are not new. Last fall, an Army intelligence bulletin warned military personnel to be vigilant after ISIS militants urged supporters to scour social media for addresses of their family members -- and to "show up [at their homes] and slaughter them." 

Fox News' Lucas Tomlinson contributed to this report. 

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.